From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BC023C44520 for ; Mon, 20 Jul 2026 15:52:41 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 16DE610E1BF; Mon, 20 Jul 2026 15:52:41 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="Lgp+DB77"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5B1F410E1BF for ; Mon, 20 Jul 2026 15:52:40 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 21F4A43CE4; Mon, 20 Jul 2026 15:52:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 977A51F00A3A; Mon, 20 Jul 2026 15:52:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784562760; bh=nGdQxqcaIC04tyTye7SFtUtqtKsuT9hgPtoDK04EPgQ=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Lgp+DB77KA0glEGY2KC3kK7SGwXXDWcymcYVLNkJX/iJPvDbZ/wjSCfHYtH9bA17q RsePj2B38Hza3XWDiLs1CzU/fnLKX5bX62+fwvh06ja77yT7oJQQZi4WgZnNcziRSh VU9BHGcpdQVURVCip3a40uIxVQxBDcFM40QjyPoJQPBYiP6j1ODf80N3JPqCK+XMDX xR58yaP42uYK5BpHpcXXCtwzrg/sTDz8C5aYkyGtJXHFDS0xLBT5AyjFND6xAoAfep b94bXG3sFn7ltkeJ/LAYihpSJB7yOeNE7aFPT0dHB/Y8bjZ1+lTlLG/ws9xZ8b3kDS dXfYFDM0S5zqQ== From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 01/15] drm/exynos: remove dependency on DRM simple helpers To: "Diogo Silva" Cc: Frank.Li@kernel.org, neil.armstrong@linaro.org, wsa+renesas@sang-engineering.com, imx@lists.linux.dev, linux-amlogic@lists.infradead.org, dri-devel@lists.freedesktop.org In-Reply-To: <20260720-drm_simple_encoder_init-v2-1-5020b630668a@gmail.com> References: <20260720-drm_simple_encoder_init-v2-0-5020b630668a@gmail.com> <20260720-drm_simple_encoder_init-v2-1-5020b630668a@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 20 Jul 2026 15:52:39 +0000 Message-Id: <20260720155239.977A51F00A3A@smtp.kernel.org> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: Pre-existing issues: - [High] This problem wasn't introduced by this patch, but the DP AUX chann= el and resources registered by analogix_dp_bind() are leaked if drm_bridge_= connector_init() fails, leading to a Use-After-Free (UAF). -- --- Patch [1]: [PATCH v2 01/15] drm/exynos: remove dependency on DRM simple= helpers --- commit c403fdd838b4dabbda14312eb449cb97a7566462 Author: Diogo Silva Subject: drm/exynos: remove dependency on DRM simple helpers The simple KMS helpers are deprecated because they only add an intermediate layer between drivers and atomic modesetting. Open-code drm_simple_encoder_init() by calling drm_encoder_init() directly and providing driver-local drm_encoder_funcs. > diff --git a/drivers/gpu/drm/exynos/exynos_dp.c b/drivers/gpu/drm/exynos/= exynos_dp.c > index b805403281504..957382223956a 100644 > --- a/drivers/gpu/drm/exynos/exynos_dp.c > +++ b/drivers/gpu/drm/exynos/exynos_dp.c [ ... ] > @@ -95,7 +99,12 @@ static int exynos_dp_bind(struct device *dev, struct d= evice *master, void *data) > =20 > dp->drm_dev =3D drm_dev; > =20 > - drm_simple_encoder_init(drm_dev, encoder, DRM_MODE_ENCODER_TMDS); > + ret =3D drm_encoder_init(drm_dev, encoder, &exynos_dp_encoder_funcs, > + DRM_MODE_ENCODER_TMDS, NULL); > + if (ret) { > + drm_err(drm_dev, "Failed to initialize encoder\n"); > + return ret; > + } > =20 > drm_encoder_helper_add(encoder, &exynos_dp_encoder_helper_funcs); [Severity: High] This isn't a bug introduced by this patch, but looking further down in exynos_dp_bind(), if drm_bridge_connector_init() fails, does this code leak the DP AUX character device and resources registered by analogix_dp_bind()? Currently, if the bridge connector init fails: connector =3D drm_bridge_connector_init(dp->drm_dev, dp->plat_data.encoder= ); if (IS_ERR(connector)) { ret =3D PTR_ERR(connector); dev_err(dp->dev, "Failed to initialize bridge_connector\n"); return ret; } The error path returns directly without calling analogix_dp_unbind() to roll back the earlier success of analogix_dp_bind(). Since the component bind fails, the master DRM bind will also fail, and the component's unbind hook (exynos_dp_unbind()) is never invoked. When the devres framework later frees the struct analogix_dp_device, could the still-registered /dev/drm_dp_auxN character device cause a Use-After-Free if accessed from userspace? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260720-drm_simple= _encoder_init-v2-0-5020b630668a@gmail.com?part=3D1